I don't know if it's a Glitch

I don't know if it's a Glitch

I just got a new Galaxy S5 two days ago and I already started using it. Today just now something happened and my screen keeps blinking pink when ever I check a notification or select an app. I have know idea what happened and I don't know whether if its a glitch or its acting up. What should I do because this hasn't happened before /